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Commitments and Contingencies (Nuclear Operations) (Narrative) (Detail) - USD ($) | 3 Months Ended
--- | ---
Jun. 30, 2018 | Mar. 31, 2018
Nuclear Obligations |  |
Loss Contingencies [Line Items] |  |
Maximum liability protection per nuclear incident amount | $ 13,100,000,000 | $ 13,400,000,000

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- Definition Maximum liability protection per nuclear incident amount. + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |